The primitive man was a long-distance runner and hence could easily migrate to different continents.
“I really feel like a fish out of the water,” proclaimed the friend.
“Then that is the best thing to happen. You would now evolve faster,” dad said.
“The fish that came out of the water, moved to land to evolve into what we see around us,” mother intervened.
“So I am evolving. Tell me then how did this monkey lose hair on the body to become human?” the friend asked.
“The lobed fin fish invaded land nearly 400 million years ago and the mammals were seen 200 million years ago. In 1924, Raymond Dart, an Australian, found a skull — a 2-million-year-old fossil that had the foramen magnum under the skull, unlike other animals that have it behind the skull. The bones forming the feet were also different. They are shorter and smaller among the chimpanzees, gorillas and orangutans. It is believed the brachiating gibbon attained its bipedal posture in the arboreal habitat when gravity pulled its spine straight and then came to the terrestrial habitat,” dad said.
“What is this arboreal and terrestrial?” the friend asked.
“The arboreal refers to the tree; terrestrial refers to the land. It is believed primitive man was a long-distance runner; his muscles and foot bones seem to have adapted for this. Since the bones are small in the chimp, they could not walk effectively and lack the smoothness, precision and the long strides that man takes while running. That is the reason for the survival of the human race and also explains the migration to different continents,” mother added.
“How do you say we’re long-distance runners? Still you’ve not answered the query of the hair on the body,” the friend demanded.
“No other primates can match humans in their ability to run long distance. It is this that led to the loss of hair,” father said.
“What? You mean to say that running made us lose hair? How?” the friend asked.
“The continuous running forced the body temperature to rise and sweat pores increased. The hair would not allow the evaporation of the sweat. It would be impossible for human beings to continue to run safely without the loss of heat. Hence the loss of the hair is more of a nature than a nurture,” dad concluded.